Malet C, Jiménez-Barbero J, Bernabé M, Brosa C, Planas A
Department de Química Orgànica, CETS Institut Químic de Sarrià, Universitat Ramón Llull, Barcelona, Spain.
Biochem J. 1993 Dec 15;296 ( Pt 3)(Pt 3):753-8. doi: 10.1042/bj2960753.
The stereochemical course of the reaction catalysed by endo-1,3-1,4-beta-D-glucan 4-glucanohydrolase (EC 3.2.1.73) has been determined by 1H n.m.r. The enzyme-catalysed hydrolysis of barley beta-glucan proceeds with overall retention of the anomeric configuration, indicating that the enzyme operates through a double-displacement mechanism. The structures of the final oligosaccharide products, 3-beta-O-cellobiosyl D-glucopyranoside and 3-beta-O-cellotriosyl D-glucopyranoside, have been completely assigned by 1H- and 13C-n.m.r. spectroscopy.
通过核磁共振氢谱(1H n.m.r.)确定了内切-1,3-1,4-β-D-葡聚糖4-葡聚糖水解酶(EC 3.2.1.73)催化反应的立体化学过程。大麦β-葡聚糖的酶促水解反应在总体上保留了异头构型,这表明该酶通过双取代机制起作用。最终寡糖产物3-β-O-纤维二糖基-D-吡喃葡萄糖苷和3-β-O-纤维三糖基-D-吡喃葡萄糖苷的结构已通过核磁共振氢谱(1H-n.m.r.)和核磁共振碳谱(13C-n.m.r.)光谱完全确定。